Bone fixation rod and implantation device for insertion thereof

ABSTRACT

The present invention provides for a bone fixation device, an implantation instrument, and system which are useful in bone fixation surgeries. The bone fixation device of the instant invention allows the surgeon the ability to navigate the rod while being inserted into a pedicle screw assembly through a non-linear pathway by incrementally changing the direction of travel as desired.

CROSS REFERENCE TO RELATED APPLICATIONS

In accordance with 37 C.F.R. 1.76, a claim of priority is included in anApplication Data Sheet filed concurrently herewith. Accordingly, thepresent invention claims priority as a divisional of U.S. patentapplication Ser. No. 14/153,768, filed Jan. 13, 2014, entitled “BoneFixation Rod And Implantation Device For Insertion Thereof”, whichclaims priority as a continuation of U.S. patent application Ser. No.13/107,189, filed May 13, 2011, entitled “Bone Fixation Rod AndImplantation Device For Insertion Thereof”, now U.S. Pat. No. 8,628,535,issued on Jan. 14, 2014, which claims priority under 35 USC 119(e) tothe U.S. Provisional Patent Application No. 61/334,643, filed May 14,2010, entitled, “Bone Fixation Rod And Implantation Device For InsertionThereof”, which is now incorporated herein by reference.

FIELD OF THE INVENTION

The instant invention relates to surgical instruments useful in bonefixation procedures and methods of use thereof; and more particularly toa bone fixation rod, such as a spinal rod, and an implantationinstrument used for insertion into a plurality of pedicle screws foralignment purposes during spinal procedures.

BACKGROUND OF THE INVENTION

The central nervous system is a vital part of the human physiology thatcoordinates human activity. It is primarily made up of the brain and thespinal chord. The spinal chord is made up of a bundle of nerve tissuewhich originates in the brain and branches out to various parts of thebody, acting as a conduit to communicate neuronal signals from the brainto the rest of the body, including motor control and sensations.Protecting the spinal chord is the spinal, or vertebral, column.Anatomically, the spinal column is made up of several regions, includingthe cervical, thoracic, lumbar and sacral regions. The cervical spine ismade up of seven vertebrae and functions to support the weight of thehead. The thoracic spine is made up of 12 vertebrae and functions toprotect the organs located within the chest. Five vertebrae make up thelumbar spine. The lumbar spine contains the largest vertebra andfunctions as the main weight bearing portion of the spine. Located atthe base of the spine is the five fused vertebrae known as the sacrum.The coccyx sits at the base of the spinal column and consists of fourfused vertebrae.

Each of the vertebrae associated with the various spinal chord regionsare made up of a vertebral body, a posterior arch, and transverseprocesses. The vertebral body, often described as having a drum-likeshape, is designed to bear weight and withstand compression or loading.In between the vertebral bodies is the intervertebral disc. Theintervertebral disc is filled with a soft, gelatinous-like substancewhich helps cushion the spine against various movements and can be thesource of various diseases. The posterior arch of the vertebrae is madeup of the lamina, pedicles and facet joints. Transverse processes extendoutwardly from the vertebrae and provide the means for muscle andligament attachment, which aid in movement and stabilization of thevertebra.

While most people have fully functional spinal chords, it is notuncommon for individuals to suffer some type of spinal ailment,including spondylolisthesis, scoliosis, or spinal fractures. One of themore common disorders associated with the spinal chord is damage to thespinal discs. Damage to the discs results from physical injury, disease,genetic disposition, or as part of the natural aging process. Discdamage often results in intervertebral spacing not being maintained,causing pinching of exiting nerve roots between the discs, resulting inpain. For example, disc herniation is a condition in which the discsubstance bulges from the disc space between the two vertebrae bodies.It is the bulging of the disc material which causes impingement on thenerves, manifesting in pain to the patient. For most patients, rest andadministration of pain and anti-inflammatory medications alleviates theproblem. However, in severe cases, cases which have developed intospinal instability or severe disc degeneration, the damaged discmaterial between the vertebral bodies is removed and replaced withspinal stabilization implants. Restoration to the normal height allowsthe pressure on the nerve roots to be relieved.

There are many different approaches taken to alleviate or minimizesevere spinal disorders. One surgical procedure commonly used is aspinal fusion technique. Several surgical approaches have been developedover the years, and include the Posterior Lumbar Interbody Fusion (PLIF)procedure which utilizes a posterior approach to access the patient'svertebrae or disc space, the Transforaminal Lumbar Interbody Fusion(TLIF) procedure which utilizes a posterior and lateral approach toaccess the patient's vertebrae or disc space, and the Anterior LumbarInterbody Fusion (ALIF) which utilizes an anterior approach to accessthe patient's vertebrae or disc space. Using any of these surgicalprocedures, the patient undergoes spinal fusion surgery in which two ormore vertebrae are linked or fused together through the use of a bonespacing device and/or use of bone grafts. The resulting surgeryeliminates any movement between the spinal sections which have beenfused together.

In addition to the spinal implants or use of bone grafts, spinal fusionsurgery often utilizes spinal instrumentation or surgical hardware, suchas pedicle screws, plates, or spinal rods. Once the spinal spacersand/or bone grafts have been inserted, a surgeon places the pediclescrews into a portion of the spinal vertebrae and attaches either rodsor plates to the screws as a means for stabilization while the bonesfuse. Currently available systems for inserting the rods into pediclescrews can be difficult, particularly in light of the fact that surgeonsinstalling these rods often work in narrow surgical fields. Moreover,since patients can vary with respect to their internal anatomy resultingin varying curvatures of the spine, a surgeon may not always have alinear path or may have anatomical structures that must be maneuveredaround in order to properly insert the surgical rods into the pediclescrew assemblies. In addition to requiring surgical skill, difficulty inplacing the rods correctly into the pedicle screws can result inunnecessary increases in the time it takes a surgeon to complete thesurgical procedure. Prolonged surgery times increase the risk to thepatient. More importantly, improperly aligning the rods and pediclescrew assemblies often results in complications for the patient andrequires corrective surgical procedures.

There exists, therefore, a need for an improved bone fixation rod andbone fixation implantation instrument that can be used by a surgeon toeasily and safely insert the bone fixation rod to a plurality of embersof a bone fixation system, such as pedicle screws which have beeninserted into various bone structures.

DESCRIPTION OF THE PRIOR ART

U.S. Pat. No. 6,530,929 discloses an installation instrument forplacement of a brace or rod into pedicle screws. The instrument ismounted to anchors secured to the pedicle screws utilizing extensionscoupled to the anchors. The instrument is movable with respect to theanchors to position a brace in a position more proximate the anchors.The brace can be inserted into the pedicle screws and manipulated awayfrom the installation instrument utilizing thumb screw. However, adisadvantage associated with the installation instrument for placementof a brace or rod into pedicle screws described therein is that thebrace can not be rotated about its longitudinal axis.

U.S. Pat. No. 7,188,626 discloses methods and instruments for placing abrace or connecting element into a plurality of anchors or pediclescrews similar to U.S. Pat. No. 6,530,929. Insertion of the connectingelements is accomplished by a linear insertion method, therefore failingto teach a connecting element that can to be rotated about itslongitudinal axis.

U.S. Pat. No. 7,520,879 discloses a device for positioning a connectingelement adjacent the spinal column using minimally invasive procedures.An inserter instrument guides the connecting element from a locationremote from one or more anchors to a location proximate to the one ormore anchors. The extensions are mountable to anchors, and the inserterinstrument is mountable to the connecting element for positioning theconnecting element adjacent the anchors in a minimally invasiveprocedure. The inserter instrument does not have to be mounted to theanchors or to the anchor extensions, and are operable independently toposition the connecting element into the patient along a minimallyinvasive insertion path from a location remote from the anchorextensions. While the inserter instrument can rotate the connectingelement along its longitudinal axis, it can not be repositioned on theconnecting element to gradually rotate the connecting element in a givendirection. Moreover, it cannot be rotated about an axis normal to itslongitudinal axis.

U.S. Publication No. 2007/0078460 discloses a method and instrumentationfor performing spinal fixation surgery. A first incision is made throughthe skin and a passageway is created to the spine. A screw is insertedthrough the passageway and into a vertebra. The screw has a head portionincluding a channel. An insertion guide is operably connected to thescrew. Additional screws may each be inserted through separate incisionsor through the first incision. Insertion guides may be operablyconnected to a head portion of each screw. A sleeve may be positionedinto one insertion guide in a first position to guide a rod through atleast one other insertion guide. The sleeve is rotated to a secondposition to allow the rod to move down the slots of the insertion guidesand into the head portion of the screw. Additionally a holdinginstrument can be employed to position a rod. Two types of connectionsbetween the holding instrument and the rod are described. Theseconnections permit the rotation of the rod about its longitudinal axis,but fail to teach a rod which can be repositioned on the connectingelement to gradually rotate the connecting element in a given direction.

U.S. Published Application No. 2005/0277934 discloses a minimallyinvasive spinal fixation system used for spinal arthrodesis or motionpreservation spinal repair. The system includes a plurality of pediclescrews and an attachment assembly for connecting the pedicle screws. Theattachment assembly includes a connector for attaching to the firstscrew and second screw, and a removable guide for percutaneouslyattaching the connector to the first screw and second screw. Theremovable guide includes a number of different embodiments forconnecting the attachment assembly to the connector. A snap type lock isused to secure the attachment to the connector. While this does permitthe connector to be repositioned by rotating it about its longitudinalaxis, the repositioning can occur at only 90 degree increments.Moreover, it can not be rotated about an axis normal to the longitudinalaxis of the connector.

U.S. Pat. No. 7,892,239, and U.S. Published Application Nos.2007/0225808 and 2008/0009880 describe a system and a method forpivotably inserting an interbody spacer device into a surgical site. Thesystem includes an interbody spacer and an insertion instrument with apivotable element configured to manipulate an interbody spacer. Aplurality of teeth is formed on at least one end of the spacer andmatching teeth are formed on an insertion instrument. An exemplaryinsertion instrument includes an expandable tip configured to beinserted and mated with a gap within an interbody spacer to aid inselective retention and manipulation of the interbody spacer.

Therefore, what is needed is a bone fixation rod which does not requirea surgeon to use a predetermined, fixed linear pathway when attemptingto insert the rod into a plurality of pedicle screw assemblies. A bonefixation device, and instrumentation for insertion, which allows thesurgeon the ability to navigate the rod while being inserted into a bonefixation system, such as a pedicle screw assembly, through a non-linearpathway by incrementally changing the direction of travel is alsodesired.

SUMMARY OF THE INVENTION

The present invention provides for a bone fixation rod, and animplantation instrument for delivery of the bone fixation rod to aplurality of pedicle screws, which is useful in bone fixation surgeries.The bone fixation device as described herein provides a surgeon with adevice that can easily and safely be inserted into a plurality ofpedicle screws for alignment purposes during orthopedic procedureswithout the need for using a predetermined insertion pathway.

As such, the bone fixation rod comprises a main body having a proximateend and a distal end. Positioned at the proximate end is an implantationinstrument receiving member. The implantation instrument receivingmember has two upwardly shaped arms which connect at a base to form agenerally U-shaped configuration. A portion of the two upwardly shapedarms contain partially circular surfaces. The implantation instrumentreceiving member is constructed such that cut into a portion of theouter surface or circumference of the partially circular surface areridges or teeth. A contoured cylindrical member links the upper portionsof the upwardly shaped arms, thereby forming a cavity. The distal end ofthe bone fixation rod can be constructed to contain a tapered portion.The tapered portion may end with a pointed tip which aids the surgeon byproviding a mechanism for pushing tissue to the side as the bonefixation device is maneuvered to its final resting position within apedicle screw. The main body has a generally cylindrical, elongatedshape containing a linear portion and/or a portion containing curvature.

The bone fixation rod is designed to be engagable with an implantationinstrument. A particular embodiment of an implantation instrument of theinstant invention includes a device having a handle, a shaft, and a bonefixation rod engaging portion positioned at the distal end of theimplantation instrument. Engagement of the bone fixation rod to theimplantation instrument can be accomplished by use of opposing jawswhich are part of the bone fixation rod engaging portion and positionedat the distal end of the instrument. A lever located on the handle isused to provide the user a mechanism for opening the opposing jaws. Theopening of the opposing jaws allows for insertion and engagement withthe implantation instrument receiving area of the bone fixation rod. Inthis position, despite being engaged by the opposing jaws, the bonefixation device is capable of rotation without becoming disengaged fromthe implantation instrument. Engaging the lever to a third positionretracts the jaws into the shaft. In this position, the bone fixationrod is firmly held in place and can not pivot relative to the opposingjaws. By disengaging and engaging the lever such that the opposing jawstoggle between the three positions, the user can navigate the rod whileit is inserted into a pedicle screw assembly without being restricted toa predetermined, linear pathway. The implantation device also providesthe surgeon with the ability to maneuver the bone fixation rod in anon-linear fashion around tissue structures by incrementally changingthe direction of travel until the rod reaches its final destination.

Accordingly, it is a primary objective of the instant invention toprovide an improved bone fixation rod which is useful in bone fixationsurgeries.

It is a further objective of the instant invention to provide a bonefixation rod constructed to provide for angular adjustment duringinsertion.

It is yet another objective of the instant invention to provide a bonefixation rod which can be locked in place in order to maintain anangular position.

It is a still further objective of the invention to provide a bonefixation rod which allows a surgeon the ability to navigate the rodwhile being inserted into a pedicle screw assembly through a non-linearpathway by incrementally changing the direction of the rod until itreaches its final destination.

It is yet another objective of the instant invention to provide a bonefixation rod which does not require a surgeon to use a predetermined,fixed linear pathway when attempting to insert the rod into a pluralityof pedicle screw assemblies.

It is a still further objective of the invention to provide animplantation instrument that can engage the bone fixation device asdescribed herein.

It is a further objective of the instant invention to provide for animplantation instrument that can make incremental adjustments to thebone fixation rod as the rod is being inserted into a pedicle screwassembly.

It is yet another objective of the instant invention to provide for animplantation instrument that can maintain the angular positioning of thebone fixation rod as the rod is inserted into a pedicle screw assembly.

Other objects and advantages of this invention will become apparent fromthe following description taken in conjunction with any accompanyingdrawings wherein are set forth, by way of illustration and example,certain embodiments of this invention. Any drawings contained hereinconstitute a part of this specification and include exemplaryembodiments of the present invention and illustrate various objects andfeatures thereof.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a prospective view of the bone fixation rod of the instantinvention;

FIG. 2 is a side view of the bone fixation rod of the instant invention;

FIG. 3 is a longitudinal cross sectional view of the bone fixation rodof the instant invention;

FIG. 4 is a front plan view of the bone fixation rod of the instantinvention;

FIG. 5 is a prospective view of an alternative embodiment of the bonefixation device, showing a partial cut view of a separable implantationreceiving member;

FIG. 6 is a prospective view of an alternative embodiment of the bonefixation device, showing the separation features positioned along themain body;

FIG. 7 illustrates the attachment of the bone fixation rod of theinstant invention to an implantation instrument;

FIG. 8 illustrates the distal end of the bone fixation rod illustratedin FIG. 5;

FIG. 9A represents an alternative embodiment of an implantationinstrument shown with a lever in a first position which corresponds toopposing jaws in an open position;

FIG. 9B illustrates the implantation instrument of FIG. 9A with thelever in a second position. Although not illustrated in the figure, thisposition allows the opposing jaws to engage the bone fixation device;

FIG. 9C illustrates the implantation instrument of FIG. 9A with thelever in a third position in which the opposing jaws have been closed.Although not illustrated in the figure, this position allows the teethassociated with two upwardly shaped arms of the implantation instrumentreceiving member of the bone fixation rod to engage the teeth area ofthe implantation instrument, thereby locking the rod in place;

FIG. 10 is a longitudinal cross sectional view of the implantationinstrument illustrated in FIGS. 9A-9C;

FIG. 11 is longitudinal cross sectional top view of the implantationdevice illustrated in FIGS. 9A-9C;

FIG. 12 illustrates a blown-up view of the teeth receiving areapositioned at the distal end of the implantation instrument as shown inFIG. 10 without the opposing jaws.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is susceptible of embodiment in variousforms, there is shown in the drawings and will hereinafter be describeda presently preferred, albeit not limiting, embodiment with theunderstanding that the present disclosure is to be considered anexemplification of the present invention and is not intended to limitthe invention to the specific embodiments illustrated.

Referring now to FIGS. 1-4, a bone fixation device will now bedescribed. While the bone fixation device will be described as a spinalrod associated with a pedicle screw assembly of a spinal fixationdevice, one of skill in the art would recognize that suchinstrumentation is not limited to spinal fixation devices and may beapplied to other applications and other bone fixation systems as well.The unique aspect of the bone fixation device of the instant inventionis that it is constructed to provide for angular adjustment duringinsertion and can be locked in place in order to maintain an angularposition. In addition, the bone fixation device of the instant inventiongives the user the ability to infinitely reposition an implantationinstrument with respect to the bone fixation device, thereby providingan advantage over the prior art rods by permitting the user to make verysmall, incremental adjustments to the bone fixation device as the deviceis being inserted.

As used herein, the term “proximate end” defines the end closest to theuser, i.e. surgeon, when in use.

As used herein, the “distal end” is defined as the end located farthestfrom the user and closest to the bone anchor device, i.e. a pediclescrew, when in use.

As used herein, “pedicle screw” or “pedicle screw assembly” is used todescribe commonly used orthopedic or spinal surgical instrumentation,individually or as a unit, such as described in U.S. Pat. No. 7,066,937.While many embodiments of a pedicle screw exist commercially, thetypical pedicle screw assembly consists generally of the pedicle screwcontaining a threaded portion which is inserted into a bone or spinalvertebrae. Connected to the screw is a housing unit having upwardlyshaped arms which form a U-shape unit. The housing unit is generallyconstructed to receive a longitudinal or spinal rod. The longitudinal orspinal rod is set to the housing through use of a set screw which can bedesigned to screw into a threaded portion of the housing to lock the rodinto place. This general construction scheme allows the surgeon toconnect and secure adjacent bones together through use of the pediclescrew assembly, thereby providing stability temporarily until the bonesheal or, if needed, permanently.

FIGS. 1 and 2 illustrate the bone fixation device 10 of the instantinvention comprising a main body 12, a proximate end 14 and a distal end16. Positioned at the proximate end 14 is an implantation instrumentreceiving member 18 constructed to provide angular adjustment to the rodduring insertion. The implantation instrument receiving member 18 hastwo upwardly shaped arms 20 and 22 connected at a base 24 to form agenerally U-shaped configuration. The two upwardly shaped arms 20 and 22have a flat surface 26 and 28 (FIG. 3), respectively, and a partiallycircular surface 30 and 32, respectively. The implantation instrumentreceiving member 18 contains engagement members, illustrated herein as aplurality of ridges or teeth, 34 a, associated with the upwardly shapedarm 20, and 34 b, associated with the upwardly shaped arm 22, cut into aportion of the outer surface or circumference of the partially circularsurfaces 30 and 32. The plurality of teeth disposed about the outersurface or circumference allow for an implantation instrument to firmlygrip the implantation instrument member 18 and aid in the manipulationof the spinal rod 10 during insertion into the pedicle screws. Inaddition to the plurality of teeth 34 a and 34 b, disposed on the outersurface or circumference of one or both of the partially circularsurfaces 30 and 32 can be other frictional features such as protrudingfeatures, materials, or rough surfaces to pivotably direct the spinalrod 10 during implantation into the pedicle screws. A contouredcylindrical member 36 links the upwardly shaped arms 20 and 22, see FIG.2 and FIG. 4, and forms a cavity 38. The cylindrical member and thecavity 38 form an implantation instrument receiving area 39 whichcouples the instrument receiving member 18 to a first portion of animplantation instrument. The distal end 16 contains a tapered portion 40with or without a pointed tip 42. While FIG. 2 illustrates a pointedtapered end, the distal end could be any shape including round, oval,square, polygonal, or the like.

The main body 12, as illustrated in FIG. 3, is shown as a cylindrical,elongated member containing a portion which is generally linear 44,i.e., having no or little curvature, and a portion containing curvature46. Because the main body 12 is illustrated as a generally cylindricalbody, it has a rounded diameter. The diameter size can be varieddepending on the need of the user. However, it is not necessary that themain body retain the round-shaped diameter. The main body 12 can beconstructed to contain curvature in varying degrees. The length of thebone fixation device 10 can be varied depending on the need of the user.The main body 12 can also be constructed without curvature. The bonefixation rod 10 is preferably made of surgical grade stainless steel,but can be made of other materials such as titanium, aluminum, an alloy,carbon fiber composite, or a polymer, such as polyvinyl chloride (PVC),polyethylene, polyesters of various sorts, polycarbonate, Teflon coatedmetal, polyetheretherketone (PEEK), or ultra high molecular weightpolyethylene (UHMWPE). Additionally, the bone fixation rod 10 can bemade to be radiolucent or radioopaque.

The implantation instrument receiving member 18 may be made of the samematerial as the main body 12 and may be integrally formed with the mainbody 12. Alternatively, implantation instrument receiving member 18 maybe constructed from a different material than that used for the mainbody. The implantation instrument receiving member 18 may be designed sothat once the main body 12 is in its proper alignment, the implantationinstrument receiving member 18 can be removable. Such functionality canbe accomplished in a variety of ways. FIG. 5 illustrates an alternativeembodiment of the bone fixation device 10. As shown in the partial cutout view, the bone fixation device comprises an implantation instrumentreceiving member 18 containing a protruding member 48 positioned at thedistal end 50. The protruding member 48 is sized and shaped to bereceived by a hollowed area 52 positioned within the main body 12. Inthis manner, the protruding member 48 is inserted, such as through pressfit manner, into the main body through the hollowed area 52. The fittingcan be designed such that the implantation instrument receiving member18 remains in place during the insertion process, but can be removed byadding a force that snaps it off the main body 12. As an alternative tosecuring the implantation instrument receiving member 18 to the mainbody through press fitting, a tangent pin may be inserted into the mainbody 12, extending through the protruding member 48. Removal of theimplantation instrument receiving member 18 is accomplished by removalof the pin and lifting the implantation instrument receiving member 18from the main body 12. The bone fixation device 10 may have animplantation instrument receiving member 18 which is secured to the mainbody 12 through a collar or use of a clip (not illustrated). As needed,the collar or clip can be removed and the implantation instrumentreceiving member 18 can be retrieved. Referring to FIG. 6, the bonefixation device 10 may include one or more separating features 54, suchas perforations, laser spots, fracture initiating lines, a groove whichhas a depth corresponding to a pre-determined magnitude of a fracturetorque or other force, or other mechanisms which allow the user toseparate the user implantation instrument receiving member 18 from themain body 12. Preferably, the separating features 54 allow separationbetween the two sections when a predetermined force or torque is appliedto the area, thereby snapping the implantation instrument receivingmember 18 off the main body 12. The implantation instrument receivingmember 18 may be made of a bioabsorbable material that is designed tosafely degrade over time within the body. The implantation instrumentreceiving member 18 may additionally be made to be frangible and/or of abioabsorbable material which dissolves and is absorbed in the body, suchas through the use of bioabsorbable polymers including but not limitedto polyglycolide, polyglycolide-co-rimethethylene carbonate,polyglyconate, poly-DL-lactide co-glycolide, poly-DL-lactide,polyDl-lactide-co-L-lactide, poly-L-lactide, or other bioabsorbablematerials known to one of skill in the art.

Insertion of the bone fixation rod 10 is accomplished by use of animplantation instrument. FIG. 7 illustrates the attachment of the bonefixation rod 10 to an implantation instrument 100. The implantationinstrument 100 contains a handle 102 positioned at the proximate end104. Extending from the handle 102 is a substantially cylindricalelongated shaft 106. At the distal end 108 of the implantationinstrument 100 is a bone fixation rod grasping region 109 which isconstructed and arranged to grasp the bone fixation rod 10, see FIG. 8.The handle 102 contains an actuating device, such as a lever 110,mechanically and pivotably connected to the bone fixation graspingregion through interior mechanical mechanisms (not illustrated).Manipulation of the lever allows the user to engage the implantationinstrument 100 with the implantation instrument receiving member 18 ofthe bone fixation device 10. As illustrated in FIG. 8, the bone fixationrod grasping region contains opposing jaws 112 and 114 and concavesurfaces 116 and 118. The concave surfaces each contain a plurality ofridges or teeth 120 and 122 or other frictional features designed toengage the plurality of teeth or ridges on the bone fixation device 10.In use, the opposing jaws 112 and 114 engage the contoured cylindricalmember 36 and couple and hold the bone fixation device 10 through thecavity 38. The ridges or teeth 34 a and 34 b which are cut into aportion of the outer surface of the partially circular surface 30 and 32of the implantation instrument receiving member 18 are received by theplurality of teeth 120 and 122 of the implantation instrument 100.

FIGS. 9A-9C illustrate an alternative embodiment of the implantationinstrument. The implantation instrument 200 provides the user theability to engage the bone fixation rod 10 in a similar manner asdescribed before. The implantation device 200 contains a handle 202positioned at the proximate end 204. Extending from the handle 202towards the distal end 206 is a shaft 208. The handle 202 includes alever 210, which when manipulated by the user allows opposing jaws 212and 214 to open and close, thereby engaging the proximal end of the bonefixation rod 10. FIG. 9A illustrates the lever in a first open position.This position is obtained by pulling the lever away from the handle, seearrow, causing the opposing jaws 212 and 214 to extend from the shaft ofthe body and to open by moving in opposite directions. While in thisposition, the proximal end of the bone fixation rod 10 may be insertedinto the implantation instrument through engaging the cylindrical member36 and alignment with the cavity 38. FIG. 9B illustrates the lever 210in a second position, obtained by manipulating the lever in a directiontowards the handle 202, see arrow. When the user further engages thelever to a position closer to the handle, the opposing jaws are drawncloser. As the opposing jaws move inwardly, they engage the bonefixation rod 10 (not shown) by clamping onto cylindrical member 36 whichlinks the upwardly shaped arms 20 and 22 through the cavity 38. In thesecond position, the bone fixation rod 10 is permitted to rotate aboutits longitudinal axis and to rotate about an axis that is normal to itslongitudinal axis. FIG. 9C illustrates the lever 210 in a thirdposition. As the lever 210 is drawn closer to the handle, the opposingjaws are retracted inwardly. In this position, the teeth 34 a and 34 bof the bone fixation rod 10 engage the teeth 250 (see FIG. 12, a blownup view of the distal end of the shaft 208 without the opposing jaws) ofthe teeth receiving area 216 of the implantation instrument 200 whichare positioned at the distal end of the device, in a retracted positionrelative to the opposing jaws 212 and 214. Once the lever has beenplaced in the third position, the bone fixation rod 10 is locked inplace.

FIGS. 10 and 11 are cross sectional views of the implantation instrument200. At the most proximate end of the handle 202 is a cap 218. Asdescribed previously, the lever 210 provides the user the ability tomanipulate the opposing jaws 212 and 214. The lever 210 is connected toa linking member 220 through a link pin 222 and a lever pin 224.Manipulation of lever 210 causes the draw rod 226 to move in a linearforward/backwards motion causing the opposing jaws 212 and 214 to open(forward motion) or close (backward/retracting motion). The opening andclosing of the jaws is accomplished by mechanical interconnection ofvarious elements housed within the handle and the shaft, including, butnot limited to, the draw rod 226, a slack cylinder 228, core element230, washers stacked in series 232, a slack stop 234, a return spring236, a return stop 238, a release button 240, a catch nut 242, a buttonspring 244 and a cross pin 246. Positioned throughout the shaft 208 areapertures 248 which can be utilized in sanitization techniques, such asautoclaving, to sterilize the instrument.

The present exemplary device and system provide for a pivotable bonefixation device that provides the user the ability to insert the bonefixation device in a non-linear path. The implantation instrument isdesigned to lock the bone fixation rod at multiple angles to allow forthe bone fixation rod to be pivoted in increments if the instrumentrotation is restricted such that the instrument can only be rotated lessthan the total rotation implemented to position the rod. Moreover, thebone fixation device and system provide the user the ability to easilyload, unload, and manipulate the spinal rod angle. Because of the uniquedesign as described herein, the bone fixation rod can be safely andaccurately pivoted without disengaging from the implantation instrument,eliminating the additional need for other instruments, such as pushersor persuaders.

An exemplary method of using the bone fixation device 10 may includeengaging of the bone fixation device 10 with the implantation instrument200 prior to inserting the bone fixation device into one or more membersof a bone fixation system, such as a plurality of pedicle screws. Toengage the bone fixation device 10, the lever 210 is moved to a firstposition. In this position, the draw rod 226 located in the shaft of theimplantation device 200 extends outwardly, opening the retractable jaws212 and 214. Pushing the lever 210 to the second position allows thebone fixation device 10 to be coupled to the insertion instrument 100through engagement of the retractable jaws 212 and 214 with thecylindrical portion 36 of the implantation instrument receiving member18 at the cavity 38. The engagement at this position allows the bonefixation device 10 to be rotatable. The bone fixation device is thenorientated to a desired angle and locked in place by moving the lever210 to a third position. In the third position, the draw rod 226 locatedin the shaft of the insertion device is pulled towards the proximal endcausing the engaging members 34 a and 34 b of the implantationinstrument receiving member 18 to engage the engaging members 216 of theinsertion instrument, thereby restraining the bone fixation device 10from pivoting with respect to the instrument. Once in the properorientation, the bone fixation device can be inserted into the body andaligned with pedicle screws which have been inserted into the pediclebone on the back of the spinal column. The device 10 is moved until itcan no longer follow a linear path. At that time, should the bonefixation device 10 not be completely placed within all the pediclescrews, the bone fixation device may be pivoted to provide furtherinsertion along a redirected pathway. To pivot the bone fixation deviceabout the end of the implantation instrument 200, the user redirects thelever 210 to the second position. This action disengages the coupling ofthe engagement members 34 a and 34 b of the implantation instrumentreceiving member 18 with the engagement member of the insertioninstrument 216. The bone fixation device 10 remains pivotably coupled tothe implantation instrument through engagement of the retractable jaws212 and 214. The implantation instrument can, therefore, be pivoted withrespect to the bone fixation device 10 and returned to the lockedposition by engaging the lever. The lever 210 is then engaged back tothe third position, locking the bone fixation device 10 in place. Bydisengaging and engaging the lever such that the opposing jaws togglebetween the three positions, the user can navigate the bone fixationdevice 10 while it is inserted into a pedicle screw assembly withoutbeing restricted to a predetermined, linear pathway. The implantationdevice also provides the user with the ability to maneuver the bonefixation rod in a non-linear fashion around tissue structures byincrementally changing the direction of travel until the bone fixationdevice reaches its final destination.

All patents and publications mentioned in this specification areindicative of the levels of those skilled in the art to which theinvention pertains. All patents and publications are herein incorporatedby reference to the same extent as if each individual publication wasspecifically and individually indicated to be incorporated by reference.

It is to be understood that while a certain form of the invention isillustrated, it is not to be limited to the specific form or arrangementherein described and shown. It will be apparent to those skilled in theart that various changes may be made without departing from the scope ofthe invention and the invention is not to be considered limited to whatis shown and described in the specification and any drawings/figuresincluded herein.

One skilled in the art will readily appreciate that the presentinvention is well adapted to carry out the objectives and obtain theends and advantages mentioned, as well as those inherent therein. Theembodiments, methods, procedures and techniques described herein arepresently representative of the preferred embodiments, are intended tobe exemplary and are not intended as limitations on the scope. Changestherein and other uses will occur to those skilled in the art which areencompassed within the spirit of the invention and are defined by thescope of the appended claims. Although the invention has been describedin connection with specific preferred embodiments, it should beunderstood that the invention as claimed should not be unduly limited tosuch specific embodiments. Indeed, various modifications of thedescribed modes for carrying out the invention which are obvious tothose skilled in the art are intended to be within the scope of thefollowing claims.

What is claimed is:
 1. A method of traversing a pathway with aconnecting member for bone implants comprising: providing an implantconnecting member in the form of a bone fixation rod, said bone fixationrod including a main body having a proximate end, a center portion and adistal end, said proximate end including at least one arm supporting atransversely secured cylindrical portion, a side surface of said atleast one arm including a circular surface, said circular surface havinga plurality of frictional engagement features extending thereabout;providing an implantation instrument for delivery of the implantconnecting member, said implantation instrument including a handlepositioned at a proximate end thereof and a grasping region at thedistal end thereof, said grasping region including at least one jawmember for rotatable cooperation with said cylindrical portion and atleast one concave surface for frictional cooperation with saidfrictional engagement features; providing said implantation instrumentwith a first open position whereby said at least one jaw member isextended away from a body of said implantation instrument whereby saidcylindrical surface is positionable within said at least one jaw member;providing a third position for said at least one jaw member whereby saidcircular surface having a plurality of frictional engagement featuresengages said concave surface whereby said bone fixation rod is fixedwith respect to said implantation instrument; providing a mechanicalmanipulator on said implantation instrument for movement of said atleast one jaw member between said first and said third positions,whereby said bone fixation rod is restrained from pivoting with respectto said insertion instrument.
 2. The method of traversing a pathway witha connecting member for bone implants of claim 1 wherein said proximateend of said bone fixation rod is constructed from a different materialthan said center portion and said distal end.
 3. The method oftraversing a pathway with a connecting member for bone implants of claim2, wherein said proximate end is constructed from a bioresorbablematerial.
 4. The method of traversing a pathway with a connecting memberfor bone implants of claim 1, wherein said bone fixation rod includesone or more separating features, whereby applying a predetermined forceto said separating features removes said proximal end from said centerportion and said distal end.
 5. The method of traversing a pathway witha connecting member for bone implants of claim 4, wherein said proximateend is frangible from said center portion and said distal end.
 6. Themethod of traversing a pathway with a connecting member for boneimplants of claim 4, wherein said proximal end of said bone fixation rodcontains a protruding member sized and shaped to fit within a hollowlumen within said center portion.
 7. The method of traversing a pathwaywith a connecting member for bone implants of claim 6, wherein saidproximal end is further secured to said center portion through a tangentpin.